A conventional type of apron or conveyor used on roll baling machines is disclosed in U.S. Pat. No. 3,901,007 and consists of a pair of endless link chains connected at spaced intervals by transverse bars or slats. The apron chains must be lubricated to prevent premature wear to them and to insure proper operation of the apron. In the past, the apron chains have been manually lubricated. This method of lubricating is undesirable because it is time consuming and messy. Furthermore, manual lubrication is often done improperly and/or inadequately and is often totally neglected.